On Sat, 29 Apr 2006 02:06:48 GMT, Bob wrote:

Not counting the potential tuner problems you mention, my experience is
a 102” whip with no loading will work ok on 10-20m, but on 40m and below
it sucks.
Bob


I would expect it to suck on the lower bands. I am trying to figure
out some form of loading that will be cheap and simple to use. I have
a 40 meter whip and I guess I could add the 102 to the top for a
stinger, but that would make for a long and weak (physically) antenna.

75 mobile sucks under the best of conditions. That much I know. I
may have to settle for a 75/80 meter antenna option. I am trying to
think of a way to add a base coil that may allow me to tune lower
bands more easily without upsetting the higher bands. I don't want to
tune the coil itself every time I change bands, but I wouldn't mind
bypassing the coil on those times I would rather not tune 80/40. I am
very interested in operating 60 meters mobile on a regular basis as
well as 20 and up.

Buck


--
73 for now
Buck
N4PGW

On Fri, 28 Apr 2006 22:57:40 -0400, Buck wrote:
I would like to use it for 75-6
meters as I am not worried about 160 meters. I would like to use it
on 75 meters, as it is the band most likely to meet the coverage I am
interested in,

Hi Buck,

All reports of short, mobile antennas on 80M generally cry crippled.
That is, unless, they are augmented by center loads under top hats a
dozen feet high or more. Even then, hardly remarkable unless you can
stand to be down 2 S-Units out the gate. For some, this knowledge is
a killer. For others who ignore it, they simply work those who can
hear them.

but also to operate all bands as I would like not to
change antennas all the time. I have loaded the 20 meter and 40 meter
antennas with it to see how it works on other bands, but they really
suck!.

Well, again, you are short on details. These two antennas (I presume
you have introduced two more to the discussion) may be air cooled
resistors for all their qualities you suggest. You might find an
object lesson here.

I don't know if it is the way they are wound or what, but
tuning the 20 for six works well, but not with other bands. Going
lower doesn't help.

Barring details....

As for the mobile vs base antennas, there may be some difference. The
problem occurs when using a quarter wave or shorter dipole.

Mobile quarterwave dipole?

However,
a quarter wave vertical is a match! This is part of my questioning.

Aside from this being natural, what could the question be?

Also, the fact that the tuner will be virtually at the antenna rather
than the coax, may make some difference, although, technically, I
think the coax would lower the reflected power to the tuner.

Many antennas are designed with a match external to them, but quite
close by. Why would this be detrimental? Even more, many antennas
are built with the match as part of them. They go by many names,
Gamma being one. Certainly nothing is lost in their use.

The theory i was hearing was that the loading coil takes all the
missing length of antenna and heats up.

Dare I say you can't trust everything you hear (read here)?

Myself, I taught RF communications in the Navy and had no trouble
whatever with the concept that a coil replaces the electrical length
missing in a short antenna. However, the Navy was never a slave to
fashion nor strict interpretation in this matter, and it was enough to
observe this quid-pro-quo as symbolic, and not literal.

I can't imagine auto-tuners
having as large a coil as this manual tuner. (It uses a wire wrapped
around a toroid of some sort. ) I imagine an autotuner uses much
smaller inductors tied together thru relays.

Indeed.

I am trying to think of a type thurmometer that I could use that
wouldn't interact with the tuner to see if it heats up.

Yuri might suggest aquarium thermometers (Liquid Crystal) - but you
would have to make sure the entire surface fit the entire strip (or
versa vice). If you have a very old digital camera, then they were
sensitive to IR. You could take a picture in the dark and resolve hot
spots.

I will probably test the antenna this weekend if I can get the parts
and time....

Further reports would be interesting.

73's
Richard Clark, KB7QHC

On Fri, 28 Apr 2006 22:07:00 -0700, Richard Clark
wrote:

On Fri, 28 Apr 2006 22:57:40 -0400, Buck wrote:
I would like to use it for 75-6
meters as I am not worried about 160 meters. I would like to use it
on 75 meters, as it is the band most likely to meet the coverage I am
interested in,

Hi Buck,

All reports of short, mobile antennas on 80M generally cry crippled.
That is, unless, they are augmented by center loads under top hats a
dozen feet high or more. Even then, hardly remarkable unless you can
stand to be down 2 S-Units out the gate. For some, this knowledge is
a killer. For others who ignore it, they simply work those who can
hear them.

I realize this. I have used a Hustler on 75 before. I was definitely
a weak signal station. I can only imagine that a tuned whip would
generate similar results, or more likely, poorer results.

but also to operate all bands as I would like not to
change antennas all the time. I have loaded the 20 meter and 40 meter
antennas with it to see how it works on other bands, but they really
suck!.

Well, again, you are short on details. These two antennas (I presume
you have introduced two more to the discussion) may be air cooled
resistors for all their qualities you suggest. You might find an
object lesson here.

There are a total of four antennas I have mentioned in here for
comparison sake. The Hustler, just mentioned above, the 102 whip with
a possible 2 foot extension, and two Antenna Specialists (AS) (look
exactly like HamSticks). I haven't had the Hustler for over a decade.
I will introduce another antenna in this message later.

The AS antennas are thin fiberglass poles with long stingers on the
top. The fiberglass poles, of course, have copper wound around them
from bottom to top, above which is a whip (stinger) about the same
length as the pole. The hustler was a center loaded trap that was
several inches in diameter and about 10-12 inches tall (the trap part)
with a stinger on top. (You are probably familiar with the Hustler.)
I also have a Volvo brand CB whip. It is a thin fiberglass whip
similar to the bottom portions of the AS antennas, but it does not
have a stinger. Like the AS antennas, the fiberglass has copper wire
wound from bottom to top with the top tightly wound and the bottom
section loosely wound. There is no stinger on top of the CB antenna.

I previously did a little experimenting with the two AS antennas and
the Volvo CB antenna (I don't have the 102 whip yet.) I used the tuner
to compare receive signals on various active bands. the results
weren't very good. Basically, each antenna performed best on the
frequencies for which they were designed (no big surprise here) but
they performed terribly on any other band. In fact, they were not
even acceptable for use on other bands. The signal strength on 20
meters, for example went from s-9 on the 20 AS antenna to less than
s-2 on the other antennas. I know others who have used the 102 steel
whip/auto-tuner combination that I have talked to never complained
that they only received s-2 signals with the system. Therefore, my
theory is that the winding of the coil on the fiberglass poles is
adversely affecting the radiation on out-of-band operation. I am
hoping that the steel whip, with or without the extension, will
perform better on all bands than any of these antennas tested. I
realize it is a compromise but the loss of an s-unit or two in
exchange for all band coverage for my mobile without having to switch
antennas or get out of the car and change taps is an acceptable
trade-off.

Remember, too, that in the original post, money is a big issue. The
purchase of a screwdriver (the best known mobile antenna design for
all band coverage) is not an option at this time. My theory is that I
should be able to mimic the 102 whip/auto-tuner results using a manual
tuner. My question is whether or not the tuner itself can hold up to
the task without being damaged.





I don't know if it is the way they are wound or what, but
tuning the 20 for six works well, but not with other bands. Going
lower doesn't help.

Barring details....

I think I addressed that above, the fiberglass poles are wrapped
tightly at the top and then loosely to the bottom, a stinger extends
from the tops of the AS antennas, and the Volvo antenna doesn't have a
stinger.


As for the mobile vs base antennas, there may be some difference. The
problem occurs when using a quarter wave or shorter dipole.

Mobile quarterwave dipole?
base. The suggestion I was given was not to use the antenna tuner on
a 20 meter dipole to tune a 40 meter frequency. This would be a 1/4
wave dipole on 40 meters. I don't know what the impedance of such an
antenna would be, but I do know that a 1/4 wave vertical is a
reasonable match. We never discussed the use of the tuner in the
mobile.



However,
a quarter wave vertical is a match! This is part of my questioning.

Aside from this being natural, what could the question be?

Also, the fact that the tuner will be virtually at the antenna rather
than the coax, may make some difference, although, technically, I
think the coax would lower the reflected power to the tuner.

Many antennas are designed with a match external to them, but quite
close by. Why would this be detrimental? Even more, many antennas
are built with the match as part of them. They go by many names,
Gamma being one. Certainly nothing is lost in their use.

The theory i was hearing was that the loading coil takes all the
missing length of antenna and heats up.

I should have clarified that this statement. The internal inductor of
the tuner makes up the missing length of the antenna and heats up
which can cause damage to the antenna tuner's inductor. This is how
it was presented to me, or how I understood it. Again, the discussion
was using the tuner to tune short dipoles to transmit on lower
frequencies.


Dare I say you can't trust everything you hear (read here)?

Myself, I taught RF communications in the Navy and had no trouble
whatever with the concept that a coil replaces the electrical length
missing in a short antenna. However, the Navy was never a slave to
fashion nor strict interpretation in this matter, and it was enough to
observe this quid-pro-quo as symbolic, and not literal.

I can't imagine auto-tuners
having as large a coil as this manual tuner. (It uses a wire wrapped
around a toroid of some sort. ) I imagine an autotuner uses much
smaller inductors tied together thru relays.

Indeed.

I am trying to think of a type thurmometer that I could use that
wouldn't interact with the tuner to see if it heats up.

Yuri might suggest aquarium thermometers (Liquid Crystal) - but you
would have to make sure the entire surface fit the entire strip (or
versa vice). If you have a very old digital camera, then they were
sensitive to IR. You could take a picture in the dark and resolve hot
spots.

I will probably test the antenna this weekend if I can get the parts
and time....

Further reports would be interesting.



I have been scheduled to work this weekend. I hope to be off Sunday,
If I can, I will try testing the whip idea using the side mount on the
van and if it appears to be promising, I will drill the holes in the
roof to mount the whip there near the radio and tuner.


73's
Richard Clark, KB7QHC
73 for now

--
73 for now
Buck
N4PGW

On Fri, 28 Apr 2006 23:07:32 -0400, Buck wrote:

On Sat, 29 Apr 2006 02:06:48 GMT, Bob wrote:

Not counting the potential tuner problems you mention, my experience is
a 102” whip with no loading will work ok on 10-20m, but on 40m and below
it sucks.
Bob

with no tuning? you get acceptable match to your rig without a tuner,
would you explain more?

thanks
Buck


I just re-read your statement. Are you saying the whip without a
loading coil used thru a tuner? My first thoughts were you meant
without a tuner.

I expect that 40 and below will be a bit poor. I hope to find a
compromise of sorts where I can add a loading coil, but only change it
when I want to operate 40-80 meters, sort of a switch between the
higher and lower bands as opposed to setting it for each band. The
alternative may be to have two antennas, one for the lower bands, set
as needed per band, and one for the upper bands that only needs tuning
with the tuner. If I am lucky, I may be able to have one with a
loading coil that tunes all the lower bands relatively efficiently and
the whip for the upper bands. I can deal with two antennas, I have a
switch but my problem right now is I have separate 40, 20, 11, 10, and
6 meter antennas. If I want to change bands, I have to replace each
antenna. Likewise, if I want to add a band, I have to buy more
antennas. I just want to simplify my operation for when I am mobile.
I have a 135 foot dipole with 300 ohm feed that I can toss up in the
trees for portable operation when I want to be efficient or for
emergency operations, but for moving, I don't want to pull off the
highway and get out of my car to change antennas every time I want to
change bands.

Thanks for the input.

Buck
--
73 for now
Buck
N4PGW

Buck wrote:
I have used a Hustler on 75 before. I was definitely
a weak signal station. I can only imagine that a tuned whip would
generate similar results, or more likely, poorer results.

Following are the summarized normalized combined results
of three 75m mobile antenna shootouts held in California
during the 1980's.

0 dB - (Reference) Bugcatcher or Screwdriver with large top hat

-2 dB - Bugcatcher or Screwdriver with no top hat

-5 dB - 8.5' whip with bugcatcher base loading coil

-6 dB - Bugcatcher with Stainless Steel Loading Coil

-8 dB - Hustler High Power system

-9 dB - Outbacker

-12 dB - Hamstick

-12 dB - 11.5' whip with SGC-230 autotuner

-14 dB - 8.5' whip with SGC-230 autotuner (estimated, not measured)
--
73, Cecil http://www.qsl.net/w5dxp

Used various SGC tuners and Icom AH-4. Also tried both of SGCs dual
loaded whips with varying results. The longer two piece unit worked
surprisingly well 80-10m years ago when conditions were better, even had
some fantastic 160m mobile contacts with it. The single 7ft version
lacks on 40 and especially 80m compared to the two piece whip but
compared to an unloaded 102” CB whip, it makes the CB whip look like a
dummy load on 40m and below. This is all with an SGC-230 feeding them.
Bob


Buck wrote:
On Sat, 29 Apr 2006 02:06:48 GMT, Bob wrote:

Not counting the potential tuner problems you mention, my experience is
a 102” whip with no loading will work ok on 10-20m, but on 40m and below
it sucks.
Bob

with no tuning? you get acceptable match to your rig without a tuner,
would you explain more?

thanks
Buck

On Sat, 29 Apr 2006 07:55:47 -0400, Buck wrote:
There are a total of four antennas I have mentioned in here for
comparison sake.

Hi Buck,

They are by degrees poor, poorer and poorest.

The Hustler
You probably walked away from the best of the group here.
the 102 whip with a possible 2 foot extension
which isn't extension enough.
and two Antenna Specialists (AS)
the air-cooled resistors.

The fiberglass poles, of course, have copper wound around them
from bottom to top, above which is a whip (stinger) about the same
length as the pole.

These on something like 4 foot or longer extension poles would help
you for a cheap solution to the lower bands. Adding a top hat to the
stinger (yeah, impossible) would go further.

(I don't have the 102 whip yet.)

Get one, at hamfests they are cheaper than toilet paper.

I know others who have used the 102 steel
whip/auto-tuner combination that I have talked to never complained
that they only received s-2 signals with the system.

They would never notice on receive. The tuner made the difference.

Therefore, my
theory is that the winding of the coil on the fiberglass poles is
adversely affecting the radiation on out-of-band operation. I am
hoping that the steel whip, with or without the extension, will
perform better on all bands than any of these antennas tested.

A coil loading it halfway up would go further (AKA Bugcatcher).

I realize it is a compromise but the loss of an s-unit or two in
exchange for all band coverage for my mobile without having to switch
antennas or get out of the car and change taps is an acceptable
trade-off.

Then using a cheap tuner (with a loaded antenna), by all means, is
part of the solution.

My question is whether or not the tuner itself can hold up to
the task without being damaged.

As an all band solution, you do stand the risk of one of them being a
fire-breather. Just which is hardly predictable with any accuracy
given the vast number of variables. There is certainly a strong
correlation with longer wavelengths and short antennas. So, you might
design two systems - cheaply, of course.

Mobile quarterwave dipole?
base. The suggestion I was given was not to use the antenna tuner on
a 20 meter dipole to tune a 40 meter frequency. This would be a 1/4
wave dipole on 40 meters. I don't know what the impedance of such an
antenna would be, but I do know that a 1/4 wave vertical is a
reasonable match.

Again, you should never believe everything you hear.

A quarter wave dipole should be a snap to tune. On the other hand,
using an 80M antenna on 40M could be a bear. Also, a quarterwave
dipole is only vaguely related to a quarterwave vertical - um, let's
just say that relationship is too strained to be compared.

We never discussed the use of the tuner in the mobile.

That was the first thing you said, it would be quite close to the
proposed mount. Anyway, I have always considered it part of your
cheap solution and it has a place there.

I should have clarified that this statement. The internal inductor of
the tuner makes up the missing length of the antenna and heats up
which can cause damage to the antenna tuner's inductor. This is how
it was presented to me, or how I understood it. Again, the discussion
was using the tuner to tune short dipoles to transmit on lower
frequencies.

This is another instance of not believing everything - but it at least
this time it offers a nugget of truth. This is the spin of the wheel
of chance I mentioned above. Don't fret so much and simply try it in
the driveway. Open the tuner, fire up the rig and tune for lowest
SWR. Let go of the key and touch components to see how hot it's
gotten. You don't need infra-red analysis and toolkit of thermocouple
probes to obtain a good understanding of the situation. Repeat on all
bands.

73's
Richard Clark, KB7QHC

On Sat, 29 Apr 2006 14:19:33 GMT, Cecil Moore
wrote:

Buck wrote:
I have used a Hustler on 75 before. I was definitely
a weak signal station. I can only imagine that a tuned whip would
generate similar results, or more likely, poorer results.

Following are the summarized normalized combined results
of three 75m mobile antenna shootouts held in California
during the 1980's.

0 dB - (Reference) Bugcatcher or Screwdriver with large top hat

-2 dB - Bugcatcher or Screwdriver with no top hat

-5 dB - 8.5' whip with bugcatcher base loading coil

-6 dB - Bugcatcher with Stainless Steel Loading Coil

-8 dB - Hustler High Power system

-9 dB - Outbacker

-12 dB - Hamstick

-12 dB - 11.5' whip with SGC-230 autotuner

-14 dB - 8.5' whip with SGC-230 autotuner (estimated, not measured)


Thank you, that is good to see.

--
73 for now
Buck
N4PGW

SNIP

This is another instance of not believing everything - but it at least
this time it offers a nugget of truth. This is the spin of the wheel
of chance I mentioned above. Don't fret so much and simply try it in
the driveway. Open the tuner, fire up the rig and tune for lowest
SWR. Let go of the key and touch components to see how hot it's
gotten. You don't need infra-red analysis and toolkit of thermocouple
probes to obtain a good understanding of the situation. Repeat on all
bands.

73's
Richard Clark, KB7QHC
Thanks, After reading all this, I will be going to get the antenna. I
have a mount on side of the van. i will re-wire it so it goes to an
SO-239 connector so I can mount the tuner next to the antenna for the
test. if all is well, I will get a hole kit and set it up on the roof.

I like the bug-catcher idea, but I don't have the parts .

Thanks, again,
Buck

--
73 for now
Buck
N4PGW

On Sat, 29 Apr 2006 15:40:50 GMT, Bob wrote:

Used various SGC tuners and Icom AH-4. Also tried both of SGCs dual
loaded whips with varying results. The longer two piece unit worked
surprisingly well 80-10m years ago when conditions were better, even had
some fantastic 160m mobile contacts with it. The single 7ft version
lacks on 40 and especially 80m compared to the two piece whip but
compared to an unloaded 102” CB whip, it makes the CB whip look like a
dummy load on 40m and below. This is all with an SGC-230 feeding them.
Bob

How long is the two piece whip?
--
73 for now
Buck
N4PGW